Writing instrument



June 2, 1959 w. H. KERSTEN 2,888,907

WRITING INSTRUMENT Filed March 19, 1956 INVENTOR.

W/LL/AM KIRSTEN WWZ/M 2,888,907 @l G INSTRUMENT William H. Kersten, Sanesvilie, Wis, assignor to The Parker Pen @ompany, .ianesville, Wis., a corporation of Wisconsin Application March 19, 1956, Serial No. 572,476 4 Claims. (Cl. 120-4203) The present invention relates to writing instruments and more particularly to retractable writing instruments.

A writing instrument of the general character noted includes a barrel or holder and a writing unit in the barrel, the writing unit being movable between a retracted position in which its writing point is concealed in the barrel and a projected position in which the writing unit is exposed forwardly beyond the barrel in a Writing position.

An object of the invention is to provide a writing instrument of the foregoing general character having a writing unit movable to projected position by inertia, and having an exceedingly simple, eifective and economical arrangement for retaining the writing unit in projected position and for releasing it from such position for permitting its retraction by means contained in the instrument for retracting the unit.

Another object is to provide a writing instrument of novel and simple construction in which the Writing unit is releasably held in projected position in engagement with a fixed stop solely by gravity to be positively and non-yieldingly held against retraction by the forces imposed on the unit during writing.

A further object is to provide a writing instrument of the character noted in which the writing unit is positively and non-yieldingly held in projected position against fixed stop means to prevent retraction during writing, where in the writing unit is releasably retained in projected position solely by gravity, and wherein magnetic means is provided for retracting the unit.

It is a still further object of the invention to provide a writing instrument of the foregoing character wherein the projection latching and holding means consists solely of a forwardly facing internal shoulder on only one side of said barrel.

Still another object is to provide a writing instrument of the foregoing character wherein release of the writing unit from the stop means is effected by merely turning the instrument about its longitudinal axis.

It is a further object to provide a writing instrument of the foregoing character wherein the writing unit is retractable to retracted position by merely turning the instrument about its longitudinal axis.

A still further object is to provide a writing instrument of the foregoing character wherein there are no moving parts other than the writing unit.

Other objects and advantages of the invention will appear from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a longitudinal sectional view through a writing instrument embodying the invention, showing the writing unit in projected position;

Fig. 2 is a view similar to Fig. l but with the barrel rotated about its longitudinal axis 180 degrees from the position shown in Fig. 1 and with the writing unit in retracted position;

Fig. 3 is a sectional view taken on line 3-3 of Fig. 1;

Fig. 4 is a sectional view taken on line 4-4 of Fig. 2.

Referring in detail to the drawings, the writing instrument illustrated is of the ball point type. However, it will be understood that the invention is not limited to that kind of pen, but may be embodied in writing instruments of other types, such as nib type fountain pens. In any case, the primary consideration of the retractability of the writing unit is that the writing instrument may be safely inserted in a pocket in the point end down position without a cap covering the writing point. Thus, the writing point is retracted so that the writing composition does not soil the clothes.

The writing instrument includes a casing or barrel 5 which may be made of any desired suitable material, such as plastic or metal.

A writing unit 6 having a writing point 11 is mounted in the barrel for reciprocal sliding movement generally along the longitudinal axis of the instrument. The unit is movable between a retracted position (Fig. 2) in which the writing point is concealed within the barrel, and a projected position (Fig. l) in which the writing point 11 is exposed forwardly beyond the barrel for writing purposes. The writing unit, insofar as its function is concerned in writing, may be considered a standard or conventional ball point cartridge, and has a reservoir filled with writing composition connected to the writing point 11.

The means for retracting the writing unit, and for holding it retracted, is magnetic, taking the form of a pair of magnetic elements 7 and 8 mounted, respectively, in the rear bore portion 14 of the barrel and on the writing unit. The magnetic elements 7 and 8 are disposed in magnetically attractive arrangement so that there is always a magnetic force therebetween tending to retract the writing unit. At least one of these magnetic elements is a permanent magnet and both of them may be, if desired. Magnets of well known Alnico material have been found suitable. When only one of the elements 7, 8 is a permanent magnet, it is preferred that the element 7 be such. The magnetic element 7 is mounted in the upper bore 14 by a suitable means such as by a press fit. The element 8 may be in the form. of a plug or cap of magnetically attractable material, preferably at the extreme rear end of the writing unit. Means may be arranged for venting the interior of the writing unit such as by a hole through element 8 or otherwise as desired. The writing unit is capable of movement in retracting direction sufficiently to enable inter-engagement of the magnetic elements as illustrated in Fig. 2.

If but one of the magnetic elements 7 and S is a permanent magnet and the other is simply an element of magnetically attractable material, the polarity of the permanent magnet is immaterial. However, if both magnetic elements 7 and 8 are permanent magnets, their polarities are arranged so that they are in magnetically attractive relationship.

The writing unit may be projected by inertia, as by quickly shaking the instrument forwardly. In the projected position the rear end of the writing unit engages the shoulder 9 formed in the barrel between rear bore 14 and forward bore 13. The shoulder 9 faces forwardly and is disposed on only one side of the bore, extending no greater than half the circumference of the bore, so that the unit, when it is disengaged from the shoulder, is entirely free for retraction rearwardly beyond the shoulder into the bore 14. Preferably, magnetic element 8 is mounted at the extreme rear end of the unit and thus the shoulder 9 is engaged by magnetic element 8 when the writing unit is in projected position.

A pocket clip 10 is affixed to the barrel in any convenient manner and is disposed on the side of the barrel opposite the shoulder 9. Thus, when the instrument is held in the hand and the barrel is rotated about its longitudinal axis until the clip is up (as shown in Fig. 1), the shoulder 9 is down. This is the proper position for projecting the writing unit and for writing with the instrument. The pocket clip thus serves as an indicator for properly positioning the barrel in executing these operations.

The writing unit is projectable by inertia, and the shoulder 9 is the sole means for latching the writing unit in projected position and for holding it there. With the writing unit in retracted position and with the pocket clip up (shoulder 9 down), as shown in Fig. l, a forward shake or thrust of the instrument will project the writing instrument forwardly by inertia. The rear end of the Writing unit advances forwardly of the shoulder 9 and falls by gravity so that, when the inertia force is spent and the forward motion ceases, the writing unit drops down and ahead of shoulder 9. The writing unit is thus moved laterally (downwardly) into position for engaging the shoulder 9 solely by gravity and without the need for or use of springs, wedges, cams or followers to latch the writing unit and shoulder, and the only moving part of the writing instrument is the writing unit.

As long as the instrument is held with shoulder 9 down (clip 10 up) as is shown in Fig. l, the shoulder 9 engages the unit and provides a fixed stop for retaining the writing unit rigidly, and thus the unit will remain in projected position against the ever present magnetic retracting force, the writing forces, and all other forces tending to retract the unit. The magnetic force between magnetic elements 7 and 8, acting rearwardly on the writing unit, aids in preventing play of the unit when the unit is in projected position and the writing point is being alternately pressed against and released from the writing surface as in normal writing.

Whenever desired, the writing unit may be retracted by simply turning the barrel about its longitudinal axis. Thus, as illustrated in the drawings, when the instrument is rotated about its longitudinal axis 130 degrees from the position shown in Fig. l to position shown in Fig. 2, the writing unit falls by gravity disengaging itself from and clearing shoulder 9. This is illustrated in Fig. 2 by dotted line showings of magnetic element 8 and Writing point 11. Upon clearing the shoulder 9, the writing unit is moved by the magnetic attractive force to the fully retracted position. The magnetic elements thus provide means for urging the writing unit in retracting (rearward) direction and for releasably holding the unit in retracted position.

It will also be appreciated that the writing unit, when in the projected position, may be retracted simply by lying the writing instrument on a fiat surface such as a desk or table and allowing the instrument to roll. The instrument will come to rest when the clip rolls around to the position engaging the desk or table and thus the shoulder 9 will be located upwardly of the barrel so that the writing unit falls by gravity clear of shoulder 9 and is moved to retracted position by the magnetic attraction.

Either or both of magnetic elements 7 and 8 may be selected of such magnetic strength to provide the desired feel of forward thrust in the inertia projection operation, and the desired magnetic attractive power for retraction of the writing unit. The magnetic attraction between the elements varies inversely as the distance between them and thus the desired magnetic attractive power for retraction can be also controlled by selecting an appropriate spacing distance between shoulder 9 and the forward end of magnetic element 7.

If desired, the magnetic strength relationship between magnetic elements 7 and 8 may be predetermined such that, even after turning the barrel about its longitudinal axis so that the writing unit falls clear of shoulder 9, the writing unit is not immediately magnetically moved to the retracted position, but will only be magnetically retracted after the distance between the magnetic elements is slightly decreased, as for example, either by applying a slight pressure to the writing point or by elevating the writing point slightly above the rear end of the writing instrument.

All of the above discussed desired arrangements have the common advantages that the inner shoulder 9 is the sole means for latching and holding the writing unit in 4. projected position, that gravity alone laterally moves the unit into position for cooperating with the shoulder, and that the only moving part of the writing instrument is the writing unit itself.

I claim:

1. A writing instrument comprising: a barrel; a writing unit movable in the barrel between a projected position and a retracted position; latch means cooperating with gravity for latching and holding the unit in projected position and for releasing the unit from projected position, said latch means consisting solely of a forwardly facing internal shoulder on only one side of said barrel; and retraction means continuously urging the unit rearwardly for retracting the unit and for releasably holding the unit in retracted position; said unit being released from the shoulder by gravity upon merely turning the barrel about its longitudinal axis thereby enabling said retraction means to retract the unit to retracted position.

2. A writing instrument comprising: a barrel; a writing unit movable in the barrel between a projected position and a retracted position; retraction means continuously urging the unit rearwardly for retracting the unit and for releasably holding the unit in retracted position; the writing unit being projectable forwardly by inertia; and'latch means cooperating with gravity for latching and holding the unit in projected position and for releasing the unit from projected position, said latch means consisting solely of a forwardly facing internal shoulder on only one side of said barrel; said unit being released from the shoulder by gravity upon merely turning the barrel about its longitudinal axis thereby enabling said retraction means to retract the unit to retracted position; the Writing unit being the' only moving part of the writing instrument.

3. A writing instrument comprising: a barrel; a writing unit movable in the barrel between a projected position and a retracted position; latch means cooperating with gravity for latching and holding the unit in projected position and for releasing the unit from projected position, said latch means consisting solely of a forwardly facing internal shoulder on only one side of said barrel; and magnetic retraction means continuously urging the unit rearwardly for retracting the unit and for releasably holding the unit in retracted position; said unit being released from the shoulder by gravity upon merely turning the barrel about its longitudinal axis thereby enabling said retraction means to retract the unit to retracted position.

4. A writing instrument comprising: a barrel; a writing unit movable in the barrel between a projected position and a retracted position; latch means cooperating with gravity for latching and holding the unit in projected position and for releasing the unit from projected position, said latch means consisting solely of a forwardly facing internal shoulder on only one side of said barrel; and magnetic retraction means continuously urging the unit rearwardly for retracting the unit and for releasably holding the unit in retracted position; said magnetic retraction means including first and second magnetic elements at least one of which is a permanent magnet, said first element being disposed in said barrel rearwardly of said shoulder and said second element being disposed on the writing unit, said elements being in magnetically attractive arrangement; said unit being released from the shoulder by gravity upon merely turning the barrel about its longitudinal axis thereby enabling said retraction means to retract the unit to retracted position.

References Cited in the file of this patent UNITED STATES PATENTS 2,676,569 Schrader Apr. 27, 1954 2,683,931 Fahlgren July 20, 1954 2,693,170 Sears NOV. 2, 1954 2,711,022 Salfelder June 21, 1955 2,734,484 OSullivan Feb. 14, 1956 2,776,646 Spatz Ian. 8, 1957 

